Automotive interior trim components are utilized for door panels, instrument panels, etc. The trim components have been manufactured by layering a skin sheet adjacent a foam layer on a rigid core and laminating same to one another. U.S. Pat. No. 4,873,045 issued Oct. 10, 1989 in the name of Fujita et al. discloses a method of manufacturing an interior component which utilizes the steps of extruding a sheet of semi-molten thermoplastic resin material as a core directly onto the mold surface, positioning a skin layer having a cushioning layer on a mold with the cushion layer facing down, clamping the mold to bond the core and the skin layer together with the cushioning layer interposed therebetween. The problem with this type of method includes grain loss and limitation of designs.
Hollow bodies for unrelated applications have been produced from thermoplastic materials of a multi-layer construction as disclosed in U.S. Pat. No. 4,874,649 issued Oct. 17, 1989 in the name of Daubenbuchel et al. The patent discloses producing hollow bodies having a wall which has foamed thermoplastic material produced by an extrusion blow molding procedure. A preform is formed with a first layer and a second layer of foamable plastic material, and thereafter the preform is expanded in a blow molding process by the application of an internal pressure. The resultant form is of tubular configuration, and may be sealed closed at an end thereof.